Geriatric anesthesia

1. GERIATRIC ANAESTHESIA

2. • There are normal changes in physiology, anatomy and response to
pharmacological agents that accompany ageing.
• And the elderly patients typically presents for surgery with multiple
chronic medical conditions, in addition to acute surgical illness.
• Age is not a contraindication to anesthesia and surgery; however,
perioperative morbidity and mortality are greater in elderly than
younger surgical patients.

3. SIMILARITIES BETWEEN ELDERLY AND
INFANTS
• Decreased ability to increase heart rate in response to hypovolemia,
hypotension or hypoxia
• Decreased lung compliance
• Decreased arterial oxygen tension
• Impaired ability to cough
• Decreased renal tubular function
• Increased susceptibility to hypothermia

4. Age related anatomy and physiological changes
CARDIOVASCULAR CHANGES
NORMAL PHYSIOLOGICAL CHANGES PATHOLOGICAL CHANAGES
Decreased arterial elasticity
Elevated afterload
Elevated systolic blood
pressure
Left ventricular hypertrophy
Decreased adrenergic activity
Decreased resting heart rate
Decreased maximal heart rate
Decreased baroreceptor reflex
Atherosclerosis
Coronary artery disease
Essential hypertension
Congestive heart failure
Cardiac arrhythmias
Aortic stenosis

5. RESPIRATORY CHANGES
NORMAL PHYSIOLOGICAL CHANGES PATHOPHYSILOGICAL
Decreased pulmonary elasticity
Decreased alveolar surface area
Increased residual volume
Increased closing capacity
Ventilation/perfusion mismatching
Decreased arterial oxygen tension
Increased chest wall rigidity
Decreased muscle strength
Decreased cough
Decreased maximal breathing capacity
Blunted response to hypercapnia and
hypoxia
Emphysema
Chronic bronchitis
Pneumonia

6. METABOLIC AND ENDOCRINE FUNCTION CHANGES
• Basal and maximal oxygen consumption decreases
• Decrease heat production, increase heat loss and hypothalamic
temperature regulating mechanism resets
• Diabetes leads to hyperglycemia, diabetic neuropathy and autonomic
dysfunction

7. RENAL CHANGES
NORMAL PHYSIOLOGICAL CHANGES PATHOPHYSIOLOGICAL
Decreased renal blood flow
Decreased renal plasma flow
Decreased glomerular filtration rate
Decreased renal mass
Decreased tubular function
Impaired sodium handling
Decreased concentrating ability
Decreased diluting capacity
Impaired fluid handling
Decreased drug excretion
Decreased renin–aldosterone
responsiveness
Impaired potassium excretion
Diabetic nephropathy
Hypertensive nephropathy
Prostatic obstruction
Congestive heart failure

8. • GIT CHANGES: decrease liver mass and hepatic blood flow albumin
production and rate of biotransformation decrease
• NERVOUS SYSTEM: decrease brain mass and neuronal loss, decrease
cerebral blood flow and decrease neurotransmitter production
• MUSCULOSKELETAL : decrease muscle mass, arthritic joints interferes
with positioning, degenerative cervical spine reduces extension

9. PHARMACOLOGICAL CHANAGES
• Decrease in muscle mass and increase in body fat total body water
So, reduced volume of distribution for water soluble drugs leads to increase
in plasma concentration. And increase solubility of lipid soluble drugs leading
to decrease in plasma concentration of such drug.
• Albumin binds acidic drugs like barbiturates, benzodiazepines, opioid
agonists , α- glycoprotein binds basic drugs like local anaesthetics –
affects drug distribution and elimination
• Careful titration of anesthetic agents helps to avoid adverse side effects
and unexpected, prolonged duration. Short-acting agents, such as propofol,
desflurane, succinylcholine may be useful in elderly patients.

10. INHALATION ANAESTHETICS
• The MAC for inhalational agents is reduced
• Onset of action is faster if cardiac output is depressed, whereas it is
delayed if there is a significant ventilation/perfusion abnormality
• Recovery from anesthesia with a volatile anesthetic may be prolonged
because of an increased volume of distribution (increased body fat)
and decreased pulmonary gas exchange
• Agents that are rapidly eliminated (eg, desflurane) are good choices

11. NONVOLATILE ANAESTHETIC AGENTS
• elderly patients require lower dose for propofol, etomidate,
barbiturates, opioids, and benzodiazepines
• Although propofol may be close to an ideal induction agent in elderly
patients because of its rapid elimination, it is more likely to cause
apnea and hypotension than in younger patients
• Elderly patients require nearly 50% lower blood levels of propofol for
anesthesia than do younger patients

12. • Enhanced sensitivity to fentanyl, alfentanil, and sufentanil is primarily
pharmacodynamic
• Aging increases the volume of distribution for all benzodiazepines,
which effectively prolongs their elimination half-lives
• Midazolam requirements are generally 50% less in elderly patients,
and its elimination half-life is prolonged by about 50%

13. MUSCLE RELAXANTS
• The response to succinylcholine and other neuromuscular blockers is
unaltered by aging
• Decreased cardiac output and slow muscle blood flow, however, may
cause up to a 2-fold prolongation in the onset of neuromuscular
blockade in elderly patients
• Recovery from nondepolarizing muscle relaxants that depend on
renal excretion (eg pancuronium) may be delayed due to decreased
drug clearance
• The pharmacological profile of atracurium is not significantly affected
by age

14. EXAMPLE – Case discussion
• An 86-year-old nursing home patient is scheduled for open reduction
and internal fixation of a subtrochanteric fracture of the femur
1)What are some of the considerations in selection of premedication
for this patient?
elderly patients require lower doses of premedication, Anticholinergic
medication is rarely needed, as aging is accompanied by atrophy of the
salivary glands. These patients may be at risk for aspiration, as opioid
premedication and pain from the injury will decrease gastric emptying.
Therefore, pretreatment with an H 2antagonist or proton pump
inhibitor should be considered

15. 2)What factors might influence the choice between regional and general
anesthesia?
Advancing age is not a contraindication for either regional or general
anesthesia
3) Are there any specific advantages or disadvantages to a regional technique
in elderly patients having hip surgery?
A major advantage in regional anesthesia particularly for hip surgery is a
lower incidence of postoperative thromboembolism. This is presumably due
to peripheral vasodilation and maintenance of venous blood flow in the
lower extremities. In addition, local anesthetics inhibit platelet aggregation
and stabilize endothelial cells

16. 4) What specific factors should be considered during induction and
maintenance of general anesthesia with this patient?
subtrochanteric fracture can be associated with more than 1 L of occult
blood loss, induction with propofol may lead to an exaggerated
decrease in arterial blood pressure. Initial hypotension may be replaced
by hypertension and tachycardia during laryngoscopy and intubation.
This changes in blood pressure increases the risk of myocardial
ischemia. Intraoperative paralysis with a nondepolarizing muscle
relaxant improves surgical conditions and allows maintenance of a
lighter plane of anesthesia.

17. THANK YOU